Items being offered for sale in an online marketplace or other ecommerce system are typically described using multiple attributes, such as color, price, model number, manufacturer, product type, size, and the like. Entering data associated with a large number of items can be tedious and time-consuming. Additionally, managing attributes associated with many items may require significant updates when item attributes change and when new attribute categories are added to the online marketplace or other ecommerce system. Managing such systems requires significant resources to maintain software code, data repositories, user interfaces, validation rules, publishing rules, and the like.